On Wed, Oct 10, 2012 at 10:42:10AM +0200, Richard Biener wrote:
> Ah, no, make_ssa_name (TREE_TYPE (rhs), NULL) is even better. On
> the 4.7 branch you need to create a new temp var ...
Ok, here is what I've committed to trunk after bootstrap/regtest:
2012-10-10 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/54877
* tree-vect-loop.c (vect_is_simple_reduction_1): For MINUS_EXPR
use make_ssa_name instead of copy_ssa_name.
* gcc.dg/torture/pr54877.c: New test.
--- gcc/tree-vect-loop.c.jj 2012-10-05 13:21:22.000000000 +0200
+++ gcc/tree-vect-loop.c 2012-10-10 11:46:17.798891846 +0200
@@ -2382,7 +2382,7 @@ vect_is_simple_reduction_1 (loop_vec_inf
if (orig_code == MINUS_EXPR)
{
tree rhs = gimple_assign_rhs2 (def_stmt);
- tree negrhs = copy_ssa_name (rhs, NULL);
+ tree negrhs = make_ssa_name (TREE_TYPE (rhs), NULL);
gimple negate_stmt = gimple_build_assign_with_ops (NEGATE_EXPR, negrhs,
rhs, NULL);
gimple_stmt_iterator gsi = gsi_for_stmt (def_stmt);
--- gcc/testsuite/gcc.dg/torture/pr54877.c.jj 2012-10-09 20:50:43.083259039
+0200
+++ gcc/testsuite/gcc.dg/torture/pr54877.c 2012-10-09 20:51:40.463941703
+0200
@@ -0,0 +1,23 @@
+/* PR tree-optimization/54877 */
+/* { dg-do run } */
+/* { dg-options "-ffast-math" } */
+
+extern void abort (void);
+
+int
+foo (void)
+{
+ double d;
+ int i;
+ for (i = 0, d = 0; i < 64; i++)
+ d--;
+ return (int) d;
+}
+
+int
+main ()
+{
+ if (foo () != -64)
+ abort ();
+ return 0;
+}
Jakub
